U.S. patent application number 10/042255 was filed with the patent office on 2002-07-18 for method and apparatus for image reading that includes an effective grounding.
Invention is credited to Inage, Osamu.
Application Number | 20020092909 10/042255 |
Document ID | / |
Family ID | 18872542 |
Filed Date | 2002-07-18 |
United States Patent
Application |
20020092909 |
Kind Code |
A1 |
Inage, Osamu |
July 18, 2002 |
Method and apparatus for image reading that includes an effective
grounding
Abstract
An image reading apparatus includes a frame, a light source, a
photo-electronic converting element, and a flexible plate. The
frame is activated for a reciprocating movement. The light source
emits light to irradiate an image surface of an original and is
held by the frame. The photo-electronic converting element receives
the light emitted by the light source and which is reflected by the
image surface of the original. In addition, the photo-electronic
converting element converts the light to an analog image signal.
The flexible plate includes a first printed wire for applying a
driving voltage to the light source, and a second printed wire for
establishing a ground to the frame.
Inventors: |
Inage, Osamu; (Tokyo,
JP) |
Correspondence
Address: |
OBLON SPIVAK MCCLELLAND MAIER & NEUSTADT PC
FOURTH FLOOR
1755 JEFFERSON DAVIS HIGHWAY
ARLINGTON
VA
22202
US
|
Family ID: |
18872542 |
Appl. No.: |
10/042255 |
Filed: |
January 11, 2002 |
Current U.S.
Class: |
235/454 |
Current CPC
Class: |
G06K 7/10643
20130101 |
Class at
Publication: |
235/454 |
International
Class: |
G06K 007/14 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 12, 2001 |
JP |
2001-004338 |
Claims
What is claimed is:
1. An image reading apparatus, comprising: a frame configured to
move in a reciprocating fashion; a light source held by the frame
and configured to emit light so as to irradiate an image surface of
an original; a photo-electronic converting element configured to
receive light reflected by the image surface of the original and to
convert the received light into an analog image signal; and a
flexible plate configured to connect the light source to a voltage
source for applying a driving voltage to the light source, said
flexible plate including a first printed wire configured to apply a
driving voltage to the light source, and including a second printed
wire configured to establish a ground to the frame.
2. The apparatus as defined in claim 1, wherein the second printed
wire of the flexible plate is connected to the frame.
3. The apparatus as defined in claim 2, further comprising: a
supporting plate mounted to a position at which the flexible plate
is fixed to the frame, and configured to support the flexible
plate; and a grounding portion integrated with the second printed
wire, and being wrapped around the supporting plate to cover a
surface of the supporting plate facing the frame.
4. The apparatus as defined in claim 1, wherein the driving voltage
applied to the light source comprises a voltage having a pulse
waveform.
5. An image reading apparatus, comprising: frame means for moving
in a reciprocating fashion; light emitting means held by the frame
means and for emitting light so as to irradiate an image surface of
an original; photo-electronic converting means for receiving light
reflected by the image surface of the original and for converting
the received light into an analog image signal; and binding means
for flexibly connecting the light emitting means to a voltage means
for applying a driving voltage, said binding means including a
first printed wire for applying the driving voltage to the light
emitting means, and including a second printed wire for
establishing a ground to the frame means.
6. The apparatus as defined in claim 5, wherein the second printed
wire of the binding means is connected to the frame means.
7. The apparatus as defined in claim 6, further comprising:
supporting means mounted to a position at which the binding means
is fixed to the frame means, and for supporting the binding means;
and grounding means integrated with the second printed wire, and
being wrapped around the supporting means to cover a surface of the
supporting means facing the frame means.
8. The apparatus as defined in claim 5, wherein the driving voltage
applied to the light emitting means comprises a voltage having a
pulse waveform.
9. An image reading method, comprising: moving a frame in a
reciprocating fashion; emitting light with a light source so as to
irradiate an image surface of an original; and receiving light
reflected by the image surface of the original and converting the
received light into an analog image signal, wherein a flexible
plate connects the light source to a voltage source for applying a
driving voltage to the light source, said flexible plate including
a first printed wire for applying the driving voltage to the light
source, and including a second printed wire for establishing a
ground to the frame.
10. The method as defined in claim 9, wherein the second printed
wire of the flexible plate is connected to the frame.
11. The method as defined in claim 10, wherein the flexible plate
is supported via a supporting plate mounted to a position at which
the flexible plate is fixed to the frame, and wherein a grounding
portion integrated with the second printed wire, is wrapped around
the supporting plate to cover a surface of the supporting plate
facing the frame.
12. The method as defined in claim 9, wherein the driving voltage
applied to the light source comprises a voltage having a pulse
waveform.
Description
CROSS-REFERENCE TO A RELATED APPLICATION
[0001] This application is based on Japanese patent application,
No. JPAP2001-004338 filed on Jan. 12, 2001, in the Japanese Patent
Office, the entire contents of which are incorporated by reference
herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a method and apparatus for
reading an image, and more particularly to a method and apparatus
for providing effective grounding to eliminate or reduce unwanted
electromagnetic interference occurring in driving a light source of
an image reading apparatus.
[0004] 2. Discussion of the Background
[0005] Conventionally, image reading apparatuses (such as scanners,
etc.) drive a light source with a driving voltage having a sign
waveform by using a driving voltage generator (e.g., a light source
stabilizing apparatus) connected to the light source through a
flexible printed wiring plate. This driving method does not result
in a substantial amount of EMI (electromagnetic interference).
[0006] However, a pulse-wave form driving voltage is now commonly
used because a light source driven with a pulse-waveform generates
a larger amount of light. A problem with this type of method is
unwanted radio noise (EMI) occurs because the pulse-waveform
driving voltage has a steep change in its waveform. Therefore, it
is difficult to suppress the amount of radio noises to meet certain
EMI requirements.
[0007] One attempt to reduce unwanted radio noises occurring with
the pulse-waveform driving method is to shorten a distance between
the light source and the driving voltage generator by mounting the
driving voltage generator to a frame or a carriage holding the
light source.
[0008] However, mounting the voltage generator in this way
increases a total weight of the frame or the carriage. Further, the
load required by the motor to drive the frame or the carriage is
increased. Accordingly, a motor with a larger torque is needed,
which also increases the amount of electricity needed to drive the
motor. In addition, the cost of the motor and the power consumption
is also increased.
SUMMARY OF THE INVENTION
[0009] Accordingly, one object of the present invention is to solve
the above-noted and other problems.
[0010] Another object of the present invention is to provide a
novel image reading apparatus and method that is reduced in size
and cost, and that reduces unwanted radio noise to meet certain EMI
requirements.
[0011] The present invention solves these and other objects by
providing a novel image reading apparatus including a frame for
moving in a reciprocating fashion, a light source held by the frame
for emitting light so as to irradiate an image surface of an
original, and a photo-electronic converting element for receiving
the light reflected by the image surface of the original and for
converting the received light into an analog image signal. Also
included is a flexible plate having a first printed wire for
applying a driving voltage to the light source, and having a second
printed wire for establishing a ground to the frame. The present
invention also provides a novel image reading method.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] A more complete appreciation of the disclosure and many of
the attendant advantages thereof will be readily obtained as the
same becomes better understood by reference to the following
detailed description when considered in connection with the
accompanying drawings, wherein:
[0013] FIG. 1 is an exploded perspective view of a portion of an
image reading apparatus according to a preferred embodiment;
[0014] FIG. 2A is a schematic top view of a flexible printed wiring
plate with associated components included in the portion of the
image reading apparatus shown in FIG. 1;
[0015] FIG. 2B is a schematic front view of the flexible printed
wiring plate of FIG. 2A;
[0016] FIG. 3 is a schematic top view of a supporting plate;
[0017] FIG. 4 is a schematic top view of another supporting
plate;
[0018] FIG. 5 is a cross-sectional view taken on line A - A of FIG.
2A;
[0019] FIG. 6 is a schematic front view of the flexible printed
wiring plate with a grounding portion; and
[0020] FIG. 7 is a cross-sectional view taken on line B - B of FIG.
2A.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0021] In describing preferred embodiments illustrated in the
drawings, specific terminology is employed for the sake of clarity.
However, the disclosure of this patent specification is not
intended to be limited to the specific terminology so selected and
it is to be understood that each specific element includes all
technical equivalents that operate in a similar manner.
[0022] Referring now to the drawings, wherein like reference
numerals designate identical or corresponding parts throughout the
several views, and more particularly to FIG. 1 thereof, a light
source carriage mechanism of an image reading apparatus according
to a preferred embodiment of this patent specification will be
described.
[0023] As shown, the image reading apparatus includes a frame 1
which is mounted on rails (not shown) disposed in parallel to a
contact glass (not shown). The frame 1 carries a light source 2 and
a mirror 3 and is moved back and forth on the rails with a motor
(not shown). The light source 2 emits light so as to irradiate an
image surface of an original and the mirror 3 reflects light
reflected by an image surface of the original. The light reflected
by the mirror 3 is then reflected by two mirrors mounted to another
frame (not shown), which moves in the same direction as the frame
1, but at a speed twice as fast as the frame 1. The light is then
received by a photo-electronic converting element (not shown) and
is converted into an analog image signal.
[0024] The image reading apparatus also includes a flexible printed
wiring plate 4 for applying a driving voltage to the light source
2. Note, a top view of the flexible printed wiring plate 4 is shown
in FIG. 2A, and a front view is shown in FIG. 2B. As shown in FIG.
1, the flexible printed wiring plate 4 has a first end fixed with a
screw 5 to a base card (not shown) of the image reading apparatus
and a second end fixed with a stopper 6 to the frame 1.
[0025] Because the flexible printed wiring plate 4 is somewhat
fragile, it is preferable the wiring plate is properly secured and
protected at portions such as the first and second ends. Therefore,
a supporting plate 7 (see FIG. 3) is provided at the first end and
a supporting plate 8 (see FIG. 4) is provided at the second end
(see also FIG. 1). Further, the supporting plates 7 and 8 have a
sufficient rigidity to properly secure and protect the wiring plate
4.
[0026] Referring again to FIG. 1, the flexible printed wiring plate
4 is connected with a wire harness 10 having a connector 9. A first
end of the wire harness 10 is connected to the flexible printed
wiring plate 4 via the supporting plate 7. Further, the connector 9
is connected to a driving voltage generator (not shown), such as a
light source stabilizing apparatus, for generating a pulse-waveform
driving voltage to be applied to the light source 2.
[0027] In addition, the wiring plate 4 is connected to the light
source 2 via connectors 11, 12. In more detail, the connector 11 is
fixed to the supporting plate 8 (e.g., by soldering, etc.), and the
connector 12 attached to the light source 2 is plugged into the
connector 11.
[0028] Further, as shown in FIG. 2A, the wiring plate 4 includes a
high voltage printed pattern 13 and a grounding printed pattern 14.
The printed patterns 13 and 14 are covered by surface coating
layers 15 and 16, as illustrated in the cross-sectional view of
FIG. 5 taken on line A - A of FIG. 2A.
[0029] In addition, as shown in FIG. 6, the wiring plate 4 also
includes a grounding portion 17 integrated with the grounding
printed pattern 14. The grounding portion 17 is folded so as to
wrap around the supporting plate 8, thereby covering a surface of
the supporting plate 8 facing the frame 1, as illustrated in the
cross-sectional view of FIG. 7 taken on line B - B of FIG. 2A.
[0030] Additionally, the grounding portion 17 has a relatively
large surface area so as to provide sufficient contact with the
frame 1 when the second end of the wiring plate 4 is fixed to the
frame 1. Thus, sufficient grounding is achieved with the flexible
printed wiring plate 4. The frame 1 is also electrically connected
to the image reading apparatus via the rails (not shown).
[0031] In the image reading apparatus having the above-described
structure, the pulse-waveform driving voltage generated by the
driving voltage generator is applied to the light source 2 via the
wire harness 10 and the flexible printed wiring plate 4. Thus,
according to the present invention radio noise generated by
application of the driving voltage to the light source 2 flows
through the grounding portion 17 and are dissipated to the image
reading apparatus via the frame 1 and rails. Because this structure
efficiently functions as an EMI countermeasure around the light
source 2, the image reading apparatus according to the present
invention suppresses the degradation of an image reading accuracy
due to radio noise.
[0032] Further, because the grounding portion 17 integrated with
the grounding printed pattern 14 contacts the frame 1 with a
relatively large surface area, effective grounding is accomplished.
Additionally, when the flexible printed wiring plate 4 is fixed to
the frame 1, the grounding portion 17 is forced to firmly contact
the frame 1. Therefore, the necessary grounding is established in
an effective manner.
[0033] In addition, because sufficient grounding is achieved via
the wiring plate 4, the driving voltage generator does not have to
be mounted to the frame 1 at a position close to the light source 2
to provide the necessary protection (as is done in the background
image reading apparatus). Accordingly, a relatively low cost and
compact driving mechanism (e.g., a motor) can be used to drive the
frame 1.
[0034] Further, numerous additional modifications and variations
are possible in light of the above teachings. It is therefore to be
understood that within the scope of the appended claims, the
disclosure of this patent specification may be practiced otherwise
than as specifically described herein.
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